transient关键字的应用——《Thinking in Java》随笔032

使用transient方式修饰过的成员属性不会被写入流中，
就不用实现Externalizable接口来逐个选择成员属性。
看下面的例子（摘自Thinking in Java）：
  1 //: Logon.java
  2 package c10;
  3 
  4 import java.io.FileInputStream;
  5 import java.io.FileOutputStream;
  6 import java.io.ObjectInputStream;
  7 import java.io.ObjectOutputStream;
  8 import java.io.Serializable;
  9 import java.util.Date;
 10 
 11 /**
 12 *    @time:         下午4:37:21
 13 *    @date:         2017年5月8日
 14 *    @auther:    skyfffire
 15 *    @version:    v0.1
 16 */
 17 public class Logon implements Serializable {
 18     private static final long serialVersionUID = -1348372416300355940L;
 19     
 20     private Date date = new Date();
 21     private String username;
 22     private transient String password;
 23     
 24     Logon(String _username, String _password) {
 25         username = _username;
 26         password = _password;
 27     }
 28     
 29     /**
 30      * @return the date
 31      */
 32     public Date getDate() {
 33         return date;
 34     }
 35 
 36     /**
 37      * @param date the date to set
 38      */
 39     public void setDate(Date date) {
 40         this.date = date;
 41     }
 42     /**
 43      * @return the username
 44      */
 45     public String getUsername() {
 46         return username;
 47     }
 48     /**
 49      * @param username the username to set
 50      */
 51     public void setUsername(String username) {
 52         this.username = username;
 53     }
 54     /**
 55      * @return the password
 56      */
 57     public String getPassword() {
 58         return password;
 59     }
 60     /**
 61      * @param password the password to set
 62      */
 63     public void setPassword(String password) {
 64         this.password = password;
 65     }
 66     /**
 67      * @return the serialversionuid
 68      */
 69     public static long getSerialversionuid() {
 70         return serialVersionUID;
 71     }
 72 
 73     /* (non-Javadoc)
 74      * @see java.lang.Object#toString()
 75      */
 76     @Override
 77     public String toString() {
 78         return "Logon [date=" + date + 
 79                 ", username=" + username + 
 80                 ", password=" + password + "]";
 81     }
 82     
 83     public static void main(String[] args) {
 84         Logon a = new Logon("Hulk", "Haha");
 85         
 86         System.out.println("Logon a = " + a);
 87         
 88         try {
 89             ObjectOutputStream out = 
 90                     new ObjectOutputStream(
 91                             new FileOutputStream("Logon.out"));
 92             out.writeObject(a);
 93             out.close();
 94             
 95             // 1.线程式暂停
 96             try {
 97                 Thread.sleep(2000);
 98             } catch (Exception e) {
 99                 e.printStackTrace();
100             }
101 
102             // 2.循环式暂停
103             int seconds = 2;
104             // currentTimeMillis()获取当前系统时间
105             long t = System.currentTimeMillis() + seconds * 1000;
106             while (System.currentTimeMillis() < t);
107             
108             ObjectInputStream in = 
109                     new ObjectInputStream(new FileInputStream("Logon.out"));
110             Logon b = (Logon) in.readObject();
111             System.out.println("Logon b = " + b);
112             in.close();
113         } catch (Exception e) {
114             e.printStackTrace();
115         }
116     }
117 }
118 
119 ///:~